Control units for fire protective signaling systems



July 30, 1963 c. HARRIMAN 7 3,099,325

CONTROL UNITS FOR FIRE PROTECTIVE SIGNALING SYSTEMS Filed Sept. 30.'1960 INVENTOR. CY HARRIMAN ATTORNEYS United States Patent 3,099,825CONTROL UNITS FOR FIRE PROTECTIVE SIGNALING SYSTEMS Cy Harriman,Westport, Conn. Filed Sept. 30, 1960, Ser. No. 59,603 8 Claims. (Cl.340213) The invention here presented relates generally to remoteelectrical indicators, and relates especially to a supervising circuitto determine the integrity of a fire or other alarm system.

Audible alarm systems to warn against fire, buglars or the like are wellknown. The systems usually incorporate a plurality of detectors whichare normally electrically open but will close and complete an electricalcircuit upon sensing an alarm.

It is imperative that such systems always be operative. It is well knownthat a fire or burglar alarm system that will not function is worse thanno alarm system at all.

In view of the above, it is generally mandatory to provide a supervisorycircuit to constantly insure the integrity and operativeness of thesystem by warning of any faults.

Generally the alarm circuit of systems as above described contain one ormore vibrating bells or horns. Since such bells or horns are activatedby the rapid opening and closing of contacts, thereby making andbreaking the circuit, they must be connected in parallel across thepower supply, rather than in series. Parallel circuits, however, cannoteasily be supervised by the usual practice of maintaining a minute ortrickle flow of current in the lines. Thus, the problem is apparent. Toprovide a minute flow of current through the alarm system at all timesfor supervision purposes, the bells or horns should be connected inseries. When the bells or horns are to be activated, however, they mustbe connected in a parallel circuit to the power supply.

It is a cardinal object of this invention, therefore, to provide adetecting circuit with a plurality of bell or horn alarms which may beconveniently supervise-d by a minute flow of current.

Another primary object of this device is to provide a self supervisorycircuit that will automatically indicate the mal-function orinoperativeness of any of its component parts, by a separate troublesignal device.

Another object of the instant invention is to set forth a selfsupervisory alarm system that is relatively economical and that hasrelatively few working components.

With these objects in View, the invention consists of the novel featuresof construction and arrangement of parts which will appear in thefollowing specification and recited in the appended claims, referencebeing had to the accompanying drawing.

It will be realized that the illustration has been simplified to thegreatest possible extent for the purpose of clarity of understanding ofthe essence of this invention. The drawing is diagrammatic, :andconventional symbols have been utilized wherever possible.

Referring particularly to the drawing there is shown a plurality ofalarm detectors D1, D2, etc., to sense the desired emergency condition.

It should be noted that although the detectors should be of the normallyopen type, closing only upon the sensing of the emergency, they are nototherwise described,

3,099,825 Patented July 30, 1963 since their specific form plays no partof the present invention. Sufficient to say, however, they may be of thebimetallic type for use with a fire alarm system.

It will be seen that the detectors D1, D2 are uniformly connected inparallel across lines L1 and L2 to the opposite terminals of a directcurrent power supply 10. It should of course be realized that the powersupply 10 may be :a rectifier, a battery, or :a combination of each.Furthermore, although only one power supply is herein shown, it shouldbe understood that this is merely for the purpose of simplicity.Generally the circuit will have more than one direct current powersupply, together with the usual voltage relays and control relays toinsure a constant input of the proper voltage direct current.

One of the lines, L1 will have a plurality of alarm indicators orannunciators 11, 11' electrically connected along its length. Asillustrated, the alarm indicators or annunciators 11, 1-1, will be inseries with respect to L1.

The furthermost end of line L1 and L2 are electrically joined through ahigh resistance coil R1 forming part of a relay switch SW1 which is ofthe type that will remain electrically closed so long as no electriccurrent is supplied thereto. The resistance of R1 is suflicient toseverely limit the flow of electrical energy to a trickle therethrough.This low value of current, however, will be sufiicient to maintain relayswitch SW1 in the open position preventing any flow of electrical energythrough line L3 and trouble indicator 12. Furthermore, the low value ofelectrical energy will flow through coil R2 which forms a part of relayswitch SW2. Relay switch SW2 will normally be open, and the relativelylow trickle flow of current through coil R2 will allow the relay switchSW2 to remain open. When the system incorporates two alarm indicators orannunciators 11 and "11', relay switch SW2 will be of the double-polesingle throw type as illustrated.

The operation of this embodiment of this device then is as follows:

With the normal positions of relays SW1 and SW2, as shown in thedrawing,and so long as the detectors D1 and D2, etc. are open the flow ofcurrent will be through 11. 11', R1 and R2. Since the coil R1 has anextremely high resistance, as hereinbefore explained, there will be only:a relatively low flow of current through lines L1 and L2. This low ilowof current will maintain SW1 in the open position and will be ofinsuflicient value to efiect SW2 which will therefor, also remain in theopen position.

However, should there be a failure of the continuity in the system, theflow of current in coil R1 will either cease or be diminished. This willpermit relay switch SW1 to close and thereby complete an electricalcircuit across trouble indicator 12 through line L3. Trouble indicator12 will then call immediate attention to the fault in the circuit andthe inoperativeness of the primary alarm system.

When there is reason for an alarm, such as a fire, assuming D1, D2, etc.are temperature type detectors, one of the detectors will close, therebycompleting another circuit across lines L1 and L2. Since detectors D1,D2, etc. are relatively low resistance devices, a high current will flowfrom line L1 to line L2. This current will be suflicient to activatealarm indicators or annunciators 11 and11'. it will be remembered,however, that the alarm indicators or annunciators are still connectedin series, and horns and bells will not generally operate when connectedin series with respect to the power supply. At the moment they are to beactivated, therefore, it will be necessary to disconnect the seriescircuit and connect the plurality of alarm indicators so that they arein parallel with respect to the power supply. This is accomplishedautomatically by means of relay SW2.

It will be observed that the relatively high flow of current present atthe time of the alarm will pass through coil R2 forming a portion ofrelay SW2. The increased current will cause SW2 to close therebycompleting separate parallel circuits for each of the alarm indicatorsor annunciators 11 and 11'.

Thus, the objects of this invention are realized by providing a systemwhereby a plurality of alarm indicators or annunciators are connected inseries for supervision when not indicating an alarm, but areautomatically disconnected from said series circuit arrangement andconnected in parallel at the moment an alarm is sensed.

It is to be realized that although only two alarm indicators orannunciators 11 and 11' are illustrated, the principals of thisinvention may be utilized with even greater numbers of indicators.

Furthermore, as hereinbefore observed, the diagram is simplified for thepurpose of clarity of invention. Commercial circuits will without doubtbe additionally complicated by conventional manual alarm switches,plural alternative power supply means, manual switches for deactivatingand resetting the supervisory circuit after a fault is discovered, etc.

It will be seen that the signal system provided accom. plishes theobjects of the invention previously set forth. The circuit andoperations will be practicable, reliable and durable in all respects. Asmany detector stations as desired may be provided for, and the constantsupervision of lines by a trickle flow of current allows the detectorsto be separated from the alarm indicator by any distance with safety.Furthermore, widely separated, but constantly supervised alarm horns orbells are for the first time economically feasible.

While there are above disclosed but a limited number of embodiments ofthe structure and product of the invention herein presented, it ispossible to produce still other embodiments without departing from theinventive concept herein disclosed, and it is desired, therefore, thatonly such limitations be imposed on the appended claimsas are statedtherein, or required by the prior art.

Having thus described my invention and illustrated its use, what I claimas new and desire to secure by Letters Patent is:

1. An electrically actuated alarm circuit comprising, a plurality ofalarm indicating means, said alarm indicating means being normallyconnected in a series circuit forease of electrical supervision, andtrouble signal means to warn of a fault in said series circuit,detecting means forsensing an alarm, and means responsive to saiddetectingmeans for disconnecting said series circuit and connecting saidalarm indicating means in parallel when an alarm is sensed.

2. An electric detection system circuit comprising, an electric powersupply, a plurality of alarm indicating means normally connected inseries with respect one line from said power supply, and means forsending a. supervisory current through said alarm indicating means whenconnected in series, and alarm detection means connected from said one.line to the other line from said power supply, and switch meansresponsive to said detection means for disconnecting said alarmindicating means from in series. with respect to said power supply andconnecting the same to. in parallel with respect said power when analarm is sensed.

3. An electric detection system circuit comprising, an electric powersupply, two alarm indicating means normally connected in series withrespect one line from said power supply, and means for sending asupervisory current through said alarm indicating means when connectedin series, and alarm detection means connected from said one line to theother line from said power supply, and switch means responsive to saiddetection means for disconnecting said alarm indicating means from inseries with respect to said power supply and connecting the same to inparallel with respect said power when :an alarm is sensed, said switchmeans including a relay energizable by the closing of said alarmdetection means.

4. An electric detection system circuit comprising, an electric powersupply, two alarm indicating means normally connected in series withrespect one line from said power supply, and means for sending asupervisory current through said alarm indicating means when connectedin series, and alarm detection means connected from said one line to theother line from said power supply, and switch means responsive to saiddetection means for disconnecting said alarm indicating means from inseries with respect to said power supply and connecting the same to inparallel with respect said power when an alarm is sensed, said switchmeans including a relay energizable by the closing of said alarmdetection means, and a high resistance coil joining the end of saidlines to permit a normal flow of supervisory current through said powersupply and said lines and said relay and said alarm indicating means.

5. An electric detection system circuit comprising, an electric powersupply, two alarm indicating means normally connected in series withrespect one line from said power supply, and means for sending asupervisory current through saidalarm indicating means when connected inseries, and alarm detection means connected from said one line to theother line from said power supply, and switch means responsive to saiddetection means for disconnecting said alarm indicating means from inseries with respect to said power supply and connecting the same to inparallel with respect said power supply when an alarm is sensed, saidswitch means including a relay energizable by the closing of said alarmdetection means, and a high resistance coil joining the ends of saidlines to permit a normal flow of supervisory current through said powersupply and said lines and said relay and said alarm indicating means,said high resistance coil forming a part of a second relay having secondswitch means, said second switch means being held open by thesupervisory current flow in said high resistance coil, whereby saidsecond switch means will close when said supervisory current ceases.

6. An electric detection system circuit comprising, an electric powersupply, a plurality of alarm indicating means normally connected inseries with respect one line from said power supply, and means forsending a supervisory current'through said alarm indicating means whenconnected in series, and alarm detection means connected from said oneline to the other line from said power supply, and switch meansresponsive to said detection means for disconnecting said alarmindicating means from in series with respect to said power supply andconnecting the same to in parallel with respect said power supply whenan alarm is sensed, said switch means including a relay energizable bythe closing of said alarm detection means, and a high resistance coiljoining the ends ofsaid lines to permit a normal flow of supervisorycurrent through said power supply and said lines and said relay and saidalarm indicating means, said high resistance coil forming a part of asecond relay having second switch means, said second switch meansbeingheld open by the supervisory current flow in said high resistancecoil, where said second switch means will close when said supervisorycurrent ceases, and second trouble alarm means actuable by the closingof said second switch means.

7. In an electrical warning system for alarm conditions, the combinationof, a power supply to induce a voltage across two electricallyconducting lines, and a plurality of alarm detection means individuallyadapted to electrically close only upon the sensing of an alarmcondition and each connected from one of said conducting lines to theother of said conducting lines, and at least two alarm annuciatordevices to announce the closing of any of said alarm detection means,each of said alarm annunciator devices being connected in a seriescircuit along said one line, and switch means responsive to any of saidalarm detection means to disconnect said series circuit and connect saidalarm annunciator devices from in series to in parallel with respectsaid power supply when said alarm is sensed, and a high resistance coiljoining the ends of said lines to permit a normal flow of supervisorycurrent through said power supply and said lines and said alarmannunciator devices.

8. An electrical warning system for alarm conditions as set forth inclaim 7, wherein said alarm annunciator devices are each of thevibratory type wherein the electrical current passing therethrough whenconnected in parallel with respect said power supply will be caused tobe intermittent.

References Cited in the file of this patent UNITED STATES PATENTS 102,651,743 Williams Sept. 8, 1953 2,887,677 Arrasmith May 19, 19592,931,018 Tellefsen et a1. Mar. 29, 1960 FOREIGN PATENTS 340,383 GreatBritain Jan. 1, 1931

1. AN ELECTRICALLY ACTUATED ALARM CIRCUIT COMPRISING A PLURALITY OFALARM INDICATING MEANS, SAID ALARM INDICATING MEANS BEING NORMALLYCONNECTED IN A SERIES CIRCUIT FOR EASE OF ELECTRICAL SUPERVISION, ANDTROUBLE SIGNAL MEANS TO WARN OF A FAULT IN SAID SERIES CIRCUIT,DETECTING MEANS FOR SENSING AN ALARM, AND MEANS RESPONSIVE TO SAIDDETECTING MEANS FOR DISCONNECTING SAID SERIES CIRCUIT AND CONNECTINGSAID ALARM INDICATING MEANS IN PARALLEL WHEN AN ALARM IS SENSED.